Double-acting proportional pressure power amplifier



March 29, 1949. E. G. STAUDE 2,465,761

DOUBLE-ACTING PROPORTIONAL PRESSURE POWER AMPLIFIER Filed Dec. 8, 1943 4 Sheets-Sheet 1 'TT'. 1. r z

INVENTOR ATTORNEY March 29, 1949. STA 2,465,761

DOUBLE-ACTING PROPORTIONAL PRESSURE POWER AMPLIFIER Filed Dec. 8, 1943 4 Sheets-Sheet 2 INVENTOR SEW 9a. m

3 ATTORNEY March 29, 1949. E. G. STAUDE 2,465,761

DOUBLE-ACTING PROPORTIONAL PRESSURE. POWER AMPLIFIER Filed Dec. 8, 1943 4 Sheets-Sheet 4 5 mvsgol gy NEY 3 ATTOR Patented Mar. 29, 1249, I

DOUBLE-ACTING PROPORTIO'NAL PRES- SURE POWER AMPLIFIER Edwin G. S aude, Minneapolis, Minn. assignor of one-half to Olive B. Staude, Minneapolis,

Minn.

Application December 8,1943, Serial No. 513,647

Claims. 1

Mv invent on relates particularly to the control of any des red mechanism, by means of an improved tvne of nre sure no 'er ampl fier. over my Patent No. 2.095.841.1mon Power ampl er for motor car con ro s gran ed October 12. 1937. as for exam le in the operat on of auto ot ve e minment such, for instance as power steering rudders or e eva ors or ailerons of airplanes.

The obier-t of my invention is to provide an apparatus of the above character whereby the control of any des red mechanism to be moved can be accomplished sub tantially instantaneously. Another obiect is to provide an apparatus of the above character which is doub e act ng so that the part to be moved can be moved in e ther direction with complete and accurate control thereof at all times. Another obiect is to provide a double acting rotary vane construction for actuating the same and from which any substantial lag, in the operation by the control mechanism, is obviated. Still another object is to provide means for operating the same by means of a single fluid pump circuit in which the continuously circulating fluid passes through two vanes that are to be moved, as desired, when the fluid pump is in operation, and which permits the manual .control of the part to be moved even when the pump is out of action for any reason. A further object is to provide two proportional pressure valves, which valves act against the fluid flow when manually operated to cause a restricted passage and thereby build up a fluid pressure. and which pressure acting against the area of the valve, whichever is operated, is transmitted to the manual control for the purpose of building up a pressure feel on the manual control so the operator will have to push harder on the control as the required pressure is increased. A further object is to provide a valve structure whereby only one valve can be closed at a time. Further objects of my invention will appear from the detailed description of the same hereinafter.

While my invention is capable of embodiment in many different forms, for thepurpose of illustration I have shown only one form thereof in the accompanying drawings. in which Fig. 1"is a side elevation of an apparatus made in accordance with my invention;

Fig. 2 is a vertical section of the same taken on line 2--2 of Fig. 1;

line 3-3 of Fig. 2;

Fig. 4 is a plan view of the double actins vanes;

7 I 50. Fig. 3 is a vertical section of the same taken on Fig. 6 is a horizontal section taken on line 6-6 of F 2.

In the drawings, I have shown two cables I and 2 which are connected to any desired manual control element, not shown, in the cockpit of an airplane. These two cables I and 2 are connected to bifurcated socket members 3 and 4. respectively, which are pivoted by means of pins 5 and 6 to the upper end of a lever I. The lever I is pivotally connected by a bolt 8. having a nut 9. to a main lever ill. On the bolt 8 there is also a link I I having sockets l2 and I3 which are connected, respectively, to cables II and I5 which lead to any desired part to be moved, as for example the rudder of an airplane, the said cables I4 and I5 leading to opposite sides of said rudder so that they will, respectively, move the said rudder in opposite directions when operated manually from the cables I and 2. It will be understood, likewise, that thecables l and 2 are operated simultaneously, but in opposite directions, from a manually movable control element, not shown, contained in the airplane cockpit. Also, it willbe noted that the cable I moves said part manually in the same direction as the said part is moved by the cable II by means of power. The same is true, also, of the cables 2 and i5. 0n the side of the lever l0 there is a centering device to normally keep the manual control in middle position when not being actuated and to restore the manually operated element to middle position, comprising a boss IS on which there is mounted, by means of a pivot H, a link l8 through which passes a rod [9, having a head 20, supported within an ear 2| on the lever ill and the other end of which has a nut 22 supporting a spring 23, one end of which rests against the side of the link l8. 0n the upper end of the link l8 there is a roller 24 carried between arms 25 and 26 in which the roller is pivotally supported upon a pivot 21 having a rivet passing through the roller 24. This roller 24 operates within an angular recess 28 carried by a projection 29 on the side of the lever l. The said lever 1, below the pivot 8, has an arm 30 provided with a tooth 3| which extends into a recess 32 on a lever 33 which is keyed to a centralshaft 34 and to which it is fastened also by a split ring 35 having a bolt 36 passingv through the same and provided with a nut 31. This central shaft 34 is located within a sleeve shaft 38 on which the lever III is keyed and fastened thereto by means of a split ring 29 1 .and a bolt 0 having a nut 4| thereon. A washer l2 is located between the levers 33 and I0. As

shown in Fig. 2, the lever 33 is fastened to its pump or the motor provision is made to connect the passageways 80' shaft 34 by a Woodruil' key 43 andsthe lever I is fastened to its shaft 38 bv a Woodrufl key 44. The said two shafts 34 and 38 are supported within an end plate 45 so as to pass through a chamber 48 within a casing 41 and thence through a cover plate 48. On its left hand end, referring to Fig. 2, the shaft 34 has a reduced portion at 48 to receive an oscillating member 50 fitted over a hexagonal portion A further reduction of the shaft 34 is at 52, resulting in the shaft 54 which has a bearing 53 in the sleeve shaft 38. The oscillating member 50 has two valve operating arms 54a and 54b. The said shaft 54 has a washer 55 and a split snap ring 58 to hold it in place within the shaft 38. Also, the shaft 38 has a washer 51 and a split snap ring 58 for holding the same in place. A screw cap 58 on the cover plate 48 covers the ends of the shafts 54 and 38 against access of dust. Upper and lower bolts 80 and 8|, having nuts 82 and 83, as well as other similar bolts, hold the end plate 45 and the cover plate 48 on the casing 41, annular rubber sealing rings 84 and 85 being provided on opposite sides of the casing 41.

The said shaft 38 has formed thereon two vanes 88 and 81 having upwardly directed curved extensions 88 and 88 which oscillate in a circular cavity forming a part of the chamber 48. The vane 88 has a passageway 1| provided with conical enlargements 12 adjacent to a circular valve seat 13 cooperating with a ball valve 14. Likewise, the vane 81 has a similar passageway provided with a circular valve seat 18 and a ball valve 11. The circular cavity 10 is divided into two chambers 18 and 18 in which the vanes 88 and 81 oscillate, respectively, the said two chambers 18 and 18 being separated by an upper spacer 80 and a lower spacer 8|, secured within the casing 41 by bolts 82 and 83, respectively, having nuts 84 and 85. It will be noted from Fig. 6, that one end of the spacer 80 is carried in a recess 88 within the cover plate 48. to take the load applied to the spacer. The spacer 8| is similarly supported within the cover plate 48. The chambers 18 and 18, and connected passageways, are filled with hydraulic liquid of any desired character. The chamber 18 has an upper port 81 connected by a curved copper tube 88 extending on the outside of the cover plate 48, the lower end of said copper tube 88 being connectedto a port 88 leading to a passageway 80 in the casing 41 which communicates with an inlet port 8| of a gear pump housing 82, 83 which fits within the lower end of the casing 41. The two parts of the gear pump housing 82, 83 are fastened together by a plurality of screws 84 so as to hold in place between the same, pump gears 85 and 88. The pump gear 85 has stud shafts 81 and 88 within the two parts of the pump housing 82, 83 and the pump gear 88 has a stud shaft 88 in the pump housing 83 as well as a motorshaft 00 passing through the pump housing member 82 and thence into an electric motor |0| in a casing |02 having an annular rubber seal I03 and a motor cover plate I04, which is fastened in any desired manner to the casing 41, the latter having an end plate I 04a secured thereto as. for example, by screws I05. It will be noted that the meshing pump gears 85 and 88 have a discharge port I 08 connected to a vertical discharge passageway I01. In case, for any reason, the pump gears 85 and 88 are not being operated, as for example when there is any break down of the IM for driving the same,

and I01 for the passage of the liquid between the same and around the gear pump so as to enable the control mechanism to be operated manually. For this purpose, the passageway extends downwardly below the gear pump and is closed at the end by a plug I08. Above the plug I08 there is a horizontal passageway I08 which leads to a passageway -I III in a hardened steel ball-seat ring I, screw-threaded in the side of the casing 41, which is provided with a valve seat I I2 for a ball valve 3 normally pressed against its seat by a helical spring I i4, the other end of which rests against a screw-threaded plug I I5 in the ring I. The ring I, furthermore, has a pluralityof radially directed passageways 8 communicating with the vertical passageway |01 which is closed at its lower end by a plug |01a. The said vertical passageway 01 delivers the pressure liquid from the pump gears and 88 upwardly into the chamber 18, and when the control apparatus is not being operated and the liquid is accordingly passing by the ball valves 11 and 14, the liquid in the chamber 18 will pass out through a port 1 and thence through a copper tube 8 on the outside of the end plate 45 and thence downwardly to a port I I8 in the chamber 18, whence the liquid passes upwardly through the passageway 1| past the ball valve 14 out through the port 81, downwardly through the pipe 88 and into the passageway 80 to the inlet side of the pump gears 85 and 80.

In the operation of the apparatus made in accordance with my invention, when, for example, the cables I and 2 are moved to the left by the operator in the airplane cockpit, this not only tends to move the pivot 8 and the connected cables I4 and |5 to the left, exerting a manual force to move the rudder in a given. direction, but this results, also, in the movement of the lever arm 30 to the right, which, accordingly, moves the lever 33 to the right, thus moving the valve arm 54b'downwardly, tending to seat the ball valve 11 while simultaneously tending to move the vane 81 upwardly towards the closing 'position of said valve. This obstructs the circulation of the liquid from the gear pump 85, 88, resulting in the exertion of an upwardly directed force on the vane 61, which in turn, through the lever i0, applies power for the movement of the cables l4 and I5 towards the left. As the member 50 turns slightly to the right, in Fig. 3, when the cables I and 2 are manually moved to the left, it moves the arm 54b against the ball 11, which tends to obstruct the flow of the fluid through the passageway 15 and thereby builds up a pressure depending on the degree of pressure of the arm 54b against the ball 11. This pressure acting through the area of the passageway 15 acts against the ball 11 and against the arm 54b which reacts against the member 50, which in turn reacts counter-clockwise on the central shaft 34 (Fig. 3), then against the tooth 3| on the arm 30 of the lever 1, which pressure opposes the manual effort of a pull on the cable I to the left, in Fig. 1. As the pull on the cable I is increased to overcome the reacting pressure, the reacting pressure also increases in direct proportion tovthe ratio provided in the pressure area against the ball and the lever relationship of the arm 30 and the lever 33. This construction provides a positive reacting proportional pressure against the manual control, which is instantaneous in action because the passages and the vane spaces are full of fluid under slight circulating pressure at all times which, since the fluid,

being a liquidfcannot be compressed, acts incables I and 2 and the effort applied, which must be proportionately greater as higher pressures are required. The further fact that the pressure controlling valves 14 and 11, are acted upon by the fluid pressure to be opened. by the pressure instantly and immediately. thus reestablishing the neutral cruising circuit, is of great importance, especially where quick operation may prevent a serious accident. When the cables 'I and 2 are moved towards the right a similar manual force is applied on the cables I and II towards the right, tending to seat the ball valve 14 by the arm "a with the upward movement of the vane 00, which results in the pressure liquid from the pump 90, 90 passing upwardly through the passage I01 past the ball valve 11, through the port 1, downwardly through the curved pipe H0 and through the port H0 to the underside of the vane 66, thus exerting power moving the cables I4 and I5 toward the right.

- In case, for any reason, the pump gears 05 and 06 are not operating, the control apparatus can be operated manually without power, inasmuch as a movement of the cable I towards the left moves the cable I4 manuall towards the left, and, vice versa, a movement of the cable 2 towards the right moves the cable l5 manually toward the right. This movement of the cable I towards the left will close the ball valve I1, and, vice versa, the movement of the cable 2 to the right closes the ball valve 14, but in either of these conditions oi operation the hydraulic liquid can circulate around the stationary pump gears 05, 90 through the passageway I00. In other words, when the arm 54b is moved downwardly the vane 01 will be moved upwardly, closing the ball valve 11, whereupon the liquid in the chamber 10 will pass through the port II1, curved pipe III, port H0, past the ball valve 14, then through the port 01, the pipe 88, the passage 90, passageway I09, past the ball valve III, into the passage I01 and then to the point beneath the vane 61. When, on the other hand, the arm a is moved downwardly, this will also move the vane 60 upwardly, closing the ball valve 14, so that the liquid in the chamber 10 above the vane 00 will pass out through the port 01, pipe 00, passage 00, passageway I00, past the ball valve Ill, into the passage I01, to the chamber", through the ball valve 11 and thence by the port I", pipe H0, port H9 and chamber 18 to the point beneaththe vane 66. 1

2. In combination, a; control a part to be moved adapted to be controlled thereby, a pump adapted to circulate a pressure liquid, and

' a plurality otcscillating rotary vanes connected to said part. a-casing in which'the vanes are I moved, said vanes having valves, respectively, controlling the circulation of said pressure liquid so as to move the vanes in opposite directions, respectively, said valves, having, a connection to the control means, said vanes having ports bein adapted to obstruct the circulation of said liquid by the closing movement or each of said valves so as to exert the power oi the pressure liquid alternately on said vanes according to the position of the control means.

3. In combination, a control means, a part to be moved adapted to be controlled thereby, a pump adapted to circulate a pressure liquid, and a plurality of vanes connected to said part, a casing in which the vanes are moved, said vanes having valves, respectively, controlling the circulation of said pressure liquid so as to move the vanes in opposite directions, respectively, said valves, having a connection to the control means, said vanes having ports being adapted to obstruct the circulation of said liquid by the closing movement of each of said valves so as to exert the power 01' the pressure liquid alternately on said vanes according to the position of the control means, said connection comprising valve actuating arms.

4. In combination, a control means, a part to be moved adapted to be controlled thereby, a pump adapted to circulate a pressure liquid, and a plurality of vanes connected to said part, a casing in which the vanes are moved. said vanes having valves, respectively, controlling the circulation of said pressure liquid so as to move the vanes in opposite directions, respectively, said valves, having a lever connection to the control means, said vanes having ports being adapted to obstruct the circulation or said liquid by the closing movement of each of said valves so as to exert the power of the pressure liquid alternately on said vanes according to the position or the control means, said lever connection comprising valve actuating arms having another lever connection to the part to be moved, said two lever connections being mounted so as to be rotatable on concentric shafts.

5. In combustion, a control means, a part to be moved adapted to be controlled thereby, a pump adapted to circulate a pressure liquid, and

' a plurality oi oscillating rotary vanes connected While I have described my invention above in a plurality of vanes connected to said part, a

casing in which the vanes are moved, said vanes having valves, respectively, controlling the circulation of said pressure liquid so as to move the vanes in opposite directions, respectively, said valves, having a connection to the control means. said vanes having ports being adapted to obstruct the circulation of said liquid by the closing movement or each of said valves so as to exert the 1 power of the pressure liquid alternately onsaid vanes according tothe position oi. the control means.

to said part, acasing in which the vanes are moved, said vanes having valves, respectively controlling the circulation of said pressure liquid so as to move the vanes in opposite directions,

respectively, said valves, having a lever connection to thecontrol means, said vanes having ports being adapted to obstruct the circulation of said liquid by the closing movement of each of said valves so as to exert the power of the pressure liquid alternately on said vanes according to the position of the control means, said lever connection comprising valve actuating arms having another lever connection to the part to .be' moved. said two lever connections being' mounted so as to be rotatable on concentric shafts.

lating rotaryvanesconnectedtosaidparaa casing in which the vanes are moved, said vanes having valves, respectively controlling the circulation of said pressure liquid so as to move the vanes in opposite directions, respectively, said valves, having a, connection to the control means, said vanes having ports being adapted to obstruct the circulation of said liquid by the closing movement of each of said valves so as to exert the power of the pressure liquid alternately on said vanes according to the position of the control means, and a centering means restoring the control for said valves to its initial middle position.

7. In combination, a control means movable to and from a middle position, a part to be moved adapted to be controlled thereby, a pump adapted to circulate a pressure liquid, a plurality of oscillating rotary vanes connected to said part, a casing in which the vanes are moved, said vanes having valves, respectively, controlling the circulation of said pressure liquid so as to move the vanes in opposite directions, respectively, said valves, having a connection to the control means, said vanes having ports being adapted to obstruct the circulation of said liquid by the closing movement of each of said valves so as to exert the power of the pressure liquid alternately on said vanes according to the position of the control means, and a centering means, comprising a spring pressed detent, restoring the control for said valves to its initial middle position.

8. In combination, a manually operable control means, a manually movable work-performing part to be moved adapted to be controlled thereby, a pump adapted to circulate a pressure liquid, a plurality of vanes connected to said part, a casing in which the vanes aremoved, said vanes having valves, respectively, controlling the circulation of said pressure liquid so as to move the vanes in opposite directions, respectively, said valves, having a connection to the control means, said vanes having ports being adapted to obstruct the.circulation of said liquid by the closing movement of each of said valves so as to exert the power of the pressure liquid alternately on said vanes according to the position of the control means, and a valved by-pass permitting the manual operation of said part by conveying the flow of the liquid around the pump when the latter is not operating.

9. In combination, a manually operable control means, a manually movable work-performing part to be moved adapted to be controlled thereby, a pump adapted to circulate a pressure liquid, a plurality of vanes connected to said part, a casing in which the vanes are moved, said vanes having valves, respectively, controlling the circulation of said pressure liquid so as to move the vanes in opposite directions, respectively, said valves, having a connection to the control means, said vanes having ports being adapted to obstruct the circulation of said liquid by the closing movement of each oi! said valves so as to exert the power of the pressure liquid alternately on said vanes according to the position of the control means, and a single acting valved by-pass permitting the manual operation of said part conveying the flow of the liquid around the pump when the latter is not operating, adapted to by-pass the liquid around the pump when the vanes are moved in either direction.

10. A double acting fluid power amplifier having a pump, a fluid circuit including a chamber. fixed partitions within said chamber to divide said chamber into compartments, a vane within each of said compartments, said vanes having a common hub connecting them together and each being provided with a sleeve in the side wall of said chamber, said sleeve being connected to the work to be performed, said circuit also including passage leading from the output side of the pump into one of the said compartments to one side of its vane, a passage from the other side of the last mentioned vane to one side of the other vane, and a passage from the other side of said other vane returning to the intake side of said pump. valves located in said vanes for restricting the flow oi the fluid through said vanes, alternatively, to produce a pressure against either of said vanes when its valve is moved towards closed position, and manually operable valve controlling means connected to said valves to move said valves alternatively towards closed position, including a reverse motion mechanism operable in either direction from an initial inactive position and a spring actuated centering member for urging said reverse motion mechanism into the initial inactive position.

EDWIN G. STAUDE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,454,396 MacDonald May 8, 1923 1,468,236 Kasley Sept. 18, 1923 2,078,749 Wood Apr. 27, 1937 2,095,841 Staude Oct. 12, 1937 2,250,393 Rado July22, 1941 FOREIGN PATENTS Number Country Date 295,290 Great Britain Oct. 31, 1929 376,983 Great Britain July 21, 1932 

